A Tableau Data Extract (.tableaudataextract or .tde, now .hyper in newer versions) is a file format used by Tableau Desktop and Tableau Server to store a compressed, columnar subset of data. It's essentially a snapshot of data optimized for fast analysis and visualization within the Tableau environment. Extracts are created from various data sources, including databases, spreadsheets, and cloud services. The primary purpose of using extracts is to improve performance, especially when working with large datasets or slow data connections. By extracting the data, Tableau can perform calculations and visualizations much faster than querying the original data source directly. Extracts can be configured to refresh periodically, ensuring that the data remains up-to-date. They also allow for offline analysis, as the data is stored locally within the extract file. Tableau Data Extracts are a crucial component of Tableau's architecture, enabling users to explore and analyze data efficiently and effectively.